In a known manner, a bucket includes a leading blade equipped with wearing parts provided for their ability to penetrate the material and protect the other elements making up the bucket. Fastened on the leading blades are support-adapters having a profile nose, while the wearing parts are teeth or shields that are positioned on the support-adapter using a precise connection. This connection is temporary so that the wearing parts can be replaced after wear.
The connection between the wearing part and its support may be done by keying. To be high-performing, the keying devices must provide a rigid connection of the elements that they join. Traditionally, the assembly and disassembly of the keyings is done by using striking tools, which create a risk of injury for operators.
Also known are keying devices that do not require the use of striking tools. In that case, special restrictive equipment is necessary, in particular to disassemble the wearing part. Furthermore, the known devices are complex to manufacture and use.
FR-A-2 878 871 describes a keying connection device between a wearing part and its support. In the example of FIGS. 5 to 7, the device comprises two metal cylinders that screw onto one another and a rubber sheath placed between them. The screwing of the two cylinders deforms the sheath in a housing of the support, while the cylinders are housed in orifices of the wearing part. The connection provided by such a device lacks rigidity, efficiency and reliability. In particular, the cylinders are not systematically in a rear contact position to ensure retention of the tooth.
US-A-2009/205228 describes another connection device between a wearing part and its support. This device comprises a key, a nut, a sheath and a bearing ring. The sheath is positioned in a housing of the support. In an insertion configuration of the connection device, only the key, the nut and the ring are removable from this housing. The sheath cannot be removed from that housing without disassembling the tooth. When the device is inserted into the housing, the action of a tool makes it possible to produce a forcible engagement by friction between the key and the sheath on the one hand, and the nut and the sheath on the other hand, at the different tapered surfaces formed on those component elements of the connection device. The sheath includes a rib which, by bearing in a slot formed in the housing of the support, prevents the connection device from rotating under the action of the tool. The material of the sheath is not elastically deformable, for successive assemblies and disassemblies, under the operation conditions of the invention. This device is not fully satisfactory, in particular in terms of ease of use and wear resistance.